I made a filling device similar to some of those above, but finally got tired of having to put up with the burp and wait routine.

I decided to add a tee and a valve into the cold water line down stream of the pump and tee'd that into my tank outlet. Now I hook the hose to the city water inlet, remove the filler cap, and open the valve. When water runs out the filler cap, I know the tank is full. The biggest advantage is that now I can do something other than hold the hose while the tank is filling.

Make you one of these simple filler attachments. Screw it onto the hose you are filling with, the cut off piece of hose extends down into the filler neck, you control the flow with the valve, or cut it off completely when needed.

It's already been said but I reckon your vent is blocked. I fill using a homemade version of the filler thingy above and I can hear the vent giving up air, especially when I have the water on full blast. A little bit of investigative work is due I think

I use the little device posted by Ag&Au. I have used one of these for about 30 years now and they work just fine. I slide it into the filler neck and turn on the water to a slow flow. The pressure of the hose on the ground keeps the filler in the opening. I can then move away to do something else while the tank fills.

I enjoy reading about all the engineering "fixes" out there for a problem that really doesn't exist. At least it doesn't exist in the cases where the vents and filler necks are not damaged or malfunctioning. Cutting a T into the water lines sounds like a nice idea but far too much work for me since the filler hose system works just fine.

I had to think for a minute, but if I got it, it's really funny.
I thinks I can did got it.

Daisy

The smaller tube diameter and its length has the added benefit of allowing more air (and water when it reaches full) to escape back up the fill tube if necessary. With a larger diameter hose stuck in the filler it is possible to damage the tank with excessive pressure. I read about that happening somewhere here on Airforums. ( I'm pretty sure I didn't just make it up.)

Yes, the manual says 54 gallon FW capacity, but I think it is more like 50 gallon. I carefully filled a 6 gallon water jug to accurately measure the capacity when I sanitized the fresh water system this spring. Using a short hose section (about 10" long) attached to the jug, I used 8 full jugs plus 2 one-gallon jugs to completely fill the tank.

I believe the 1/4" hole next to the fill hole is for overflow, which I suppose would also work as a vent.

I used this opportunity to "calibrate" the Micropulse monitor, checking the reading after each jug was poured into the FW tank. Also went through the process of calibrating the gray and black water tanks; noting the readouts along the way.

Otherwise, I stuff the hose (similar to SStar's) in the inlet and let it run a slow steady stream to fill the tank. Water comes out the overfill when it is full. And yes, you should be able to find access to see the plastic tank from inside to verify the level, but it might be difficult. My tank is in the closet under the floor where the pump is mounted.

Yes, the manual says 54 gallon FW capacity, but I think it is more like 50 gallon. I carefully filled a 6 gallon water jug to accurately measure the capacity when I sanitized the fresh water system this spring. Using a short hose section (about 10" long) attached to the jug, I used 8 full jugs plus 2 one-gallon jugs to completely fill the tank.

I believe the 1/4" hole next to the fill hole is for overflow, which I suppose would also work as a vent.

I used this opportunity to "calibrate" the Micropulse monitor, checking the reading after each jug was poured into the FW tank. Also went through the process of calibrating the gray and black water tanks; noting the readouts along the way.

Otherwise, I stuff the hose (similar to SStar's) in the inlet and let it run a slow steady stream to fill the tank. Water comes out the overfill when it is full. And yes, you should be able to find access to see the plastic tank from inside to verify the level, but it might be difficult. My tank is in the closet under the floor where the pump is mounted.

Actually, the complete water capacity is about 54 to 55 gallons, if you include the water heater.

In a "have to" situation, that water is safe to use for drinking as well.

I only know how my vintage airstream works. When I camp without hookups I use a funnel to add fresh water from a bucket etc. If I pour the water in too fast the air burps out and splashes all over me. I do not have a vent sufficient to resolve this problem. A very slow pour is the only way for me.

However, the tank must be venting someway or the water pump couldn't pump the water without air getting in to fill the space left by the exiting water.

When hooked to city water I open a valve in my trailer and remove the exterior fill cap. When the tank is full the water comes out the fill tube and I know I have a full tank of water.

Works for me. I'm sure your new rig is technically far more advanced than mine and should be far more user friendly.

I only know how my vintage airstream works. When I camp without hookups I use a funnel to add fresh water from a bucket etc. If I pour the water in too fast the air burps out and splashes all over me. I do not have a vent sufficient to resolve this problem. A very slow pour is the only way for me.

However, the tank must be venting someway or the water pump couldn't pump the water without air getting in to fill the space left by the exiting water.

When hooked to city water I open a valve in my trailer and remove the exterior fill cap. When the tank is full the water comes out the fill tube and I know I have a full tank of water.

Works for me. I'm sure your new rig is technically far more advanced than mine and should be far more user friendly.